1,721,007 research outputs found
Replica symmetric evaluation of the information transfer in a two-layer network in presence of continuous and discrete stimuli
No full textIn a previous paper we have evaluated analytically the mutual information between the firing rates of N independent units and a set of multidimensional continuous and discrete stimuli, for a finite population size and in the limit of large noise. Here, we extend the analysis to the case of two interconnected populations, where input units activate output ones via Gaussian weights and a threshold linear transfer function. We evaluate the information carried by a population of M output units, again about continuous and discrete correlates. The mutual information is evaluated solving saddle-point equations under the assumption of replica symmetry, a method that, by taking into account only the term linear in N of the input information, is equivalent to assuming the noise to be large. Within this limitation, we analyze the dependence of the information on the ratio M/N, on the selectivity of the input units and on the level of the output noise. We show analytically, and confirm numerically, that in the limit of a linear transfer function and of a small ratio between output and input noise, the output information approaches asymptotically the information carried in input. Finally, we show that the information loss in output does not depend much on the structure of the stimulus, whether purely continuous, purely discrete or mixed, but only on the position of the threshold nonlinearity, and on the ratio between input and output noise
The relevance of educational poverty in Europe: Determinants and remedies
No full textThis paper explores the degree of educational poverty in European countries using data from OECD Programme for International Student Assessment (PISA). This research adopts the class of additive multidimensional poverty measures proposed by Alkire & Foster (2011) and investigates the degree of educational poverty in terms of incidence, breadth, depth and severity. Also, we analyse the impact of students’ characteristics and school-level factors on the probability of being educational poor in various learning dimensions. The findings reveal that between 2006 and 2015 the incidence of educational poverty became more relevant in many European countries, while most of them experienced a reduction of poverty depth and severity. Therefore, several policy scenarios are simulated in order to highlight the school factors that can be activate to alleviate the risk of educational poverty in the European countries that experienced the highest incidence of educational poor student
Theoretical model of neuronal population coding of stimuli with both continuous and discrete dimensions
No full textIn a recent study the initial rise of the mutual information between the firing rates of N neurons and a set of p discrete stimuli has been analytically evaluated, under the assumption that neurons fire independently of one another to each stimulus and that each conditional distribution of firing rates is gaussian. Yet real stimuli or behavioural correlates are high-dimensional, with both discrete and continuously varying features.Moreover, the gaussian approximation implies negative firing rates, which is biologically implausible. Here, we generalize the analysis to the case where the stimulus or behavioural correlate has both a discrete and a continuous dimension. In the case of large noise we evaluate the mutual information up to the quadratic approximation as a function of population size. Then we consider a more realistic distribution of firing rates, truncated at zero, and we prove that the resulting correction, with respect to the gaussian firing rates, can be expressed simply as a renormalization of the noise parameter. Finally, we demonstrate the effect of averaging the distribution across the discrete dimension, evaluating the mutual information only with respect to the continuously varying correlate
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Prosthetic-restorative approach for the restoration of tooth wear. Vdo increase, rehabilitation of anatomy and function and aesthetic restoration of anterior teeth. Case report
Full text linkObjective: This article presents a case report of combined prosthetic-adhesive rehabilitation in a patient with a generalized tooth wear.
Methods: A combined treatment adhesive - prosthetic was proposed to a male patient of 65 years old having a clinically significant tooth wear, with dentine exposure and with a reduction in clinical crown height. The erosive/abrasive worn dentition have been reconstructed with direct resin composite restorations on the posterior teeth and with zirconia crown on the anterior teeth.
Results: Direct composite restorations have a number of distinct advantages. These restorations have proved durable and aesthetic, protect tooth structure and posterior occlusal contact is predictably re-established.
Conclusions: A combinations of direct and indirect restorations, based on the new vertical dimension of occlusion (VDO), can help to reestablish anatomy and function
Restoration of anterior teeth using an indirect composite technique. Case report
Full text linkThis article presents a case report of restoration of anterior teeth using an indirect technique with composite
veneers in order to restore the dental anatomy and to provide aesthetic and function of anterior teeth. A treatment of upper anterior teeth with indirect microhybrid composite restoration was proposed to a 40-year-old woman with old discolored and fractured ceramic veneers. Upper six anterior teeth were prepared and, after impressions with VPS of maxillary arche, the composite veneers were placed. There are several advantages offered by indirect techniques compared to direct techniques. The increased practice of veneering technique with indirect composites is due to improvement in the properties of composite materials in the last years. The results are very favourable and the patient is satisfied. The restorations with composite veneers have proved durable and aesthetic, protect tooth structure and aesthetic and function is predictably
re-established
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Development of patient-based questionnaire about a esthetic and functional differences between overdenture simplant-supported and overdentures tooth-supported. Study of 43 patients with a followup of1 year
Full text linkDevelopment of patient-based questionnaire about aesthetic and functional differences between overdenturesimplant-supported and overdentures tooth-supported. Study of 43 patients with a follow up of 1 year.Objective.The aim of this study is to compare functional efficiency and patients satisfaction between tooth-supported andimplant-supported overdenture through a questionnaire that accurately reflects the real concerns of patients with dentalprosthesis.Methods.Forty-three patients were selected from the out patient clinic, Department of Dentistry “Fra G.B. Orsenigo Os-pedale San Pietro F.B.F.”, Rome, Italy.Their age were ranging from 61 to 83 years. Eighteen patients were rehabilitatedwith overdentures supported by natural teeth and twenty-five with overdentures implant-supported. Discussion and Result. The questionnaire proposed one year after the insertion of the prosthetis has showed that thereisn’t difference statistically significant in terms of function, phonetics and aesthetics between overdenture implant-supportedand tooth supported.Conclusions.The results of the questionnaire showed that the patients generally had a high level of satisfaction concernto the masticatory function, esthetics and phonetics. In addition, on average, they haven’t difficulty in removal and inser-tion of the denture and in oral hygiene. They haven’t in both groups problems related to fractures
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